Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

Luna 16 was a landmark success for the Soviets in their deep space exploration program; the mission accomplished the first fully automatic recovery of soil samples from the surface of the Moon. The success came after five failures.

After a successful coast to the Moon (which included one midcourse correction), Luna 16 entered circular lunar orbit (at 110 kilometers with a 70° inclination) on 17 September. Two further orbital adjustments on 18 and 19 September altered both altitude and inclination in preparation for descent to the Moon. At perilune at 05:12 UT on 20 September, Luna 16 fired its main engine to begin its descent to the surface. Six minutes later, the spacecraft safely soft-landed in its target area at 0°41' south latitude and 56°18' east longitude, in the northeast area of the Sea of Fertility, approximately 100 kilometers east of Webb crater. The mass of the spacecraft at landing was 1,880 kilograms.

Less than an hour after landing, at 06:03 UT, an automatic drill penetrated the lunar surface to collect a soil sample. After drilling for 7 minutes, the drill reached a stop at 35 millimeters depth and then withdrew its sample and lifted it in an arc to the top of the spacecraft, depositing the precious cargo in a small spherical capsule mounted on the main spacecraft bus. Finally, at 07:43 UT on 21 September, the spacecraft's upper stage lifted off from the Moon.

Three days later, after a direct ascent traverse with no midcourse corrections, the capsule, with its 105 grams of lunar soil, reentered Earth's atmosphere at a velocity of 11 kilometers per second. The capsule parachuted down 80 kilometers southeast of the town of Dzhezkazgan in Kazakhstan at 05:25 UT on 24 September 1970. Analysis of the dark basalt material indicated a close resemblance to soil recovered by the American Apollo 12 mission.

Key Dates

12 Sep 1970: Launch

Status: Successful

Fast Facts

This was the first fully robotic sample return from the surface of another world.

It was the Soviet Union's first successful sample return mission (following two sample return missions by America's Apollo 11 and Apollo 12).

The Soviets exchanged 3 grams of their lunar sample from Luna 16 for 3 grams each of the samples collected by Apollo 11 and 12.